Justin Bieber‘s dad is living in a pretty badass Canadian home … along with his two kids … but TMZ has learned, JB is the one who sprung for the place.

Sources connected to the Bieber family tell us … Justin wants to make sure his half-brother and half-sister are living in a really nice home, so he shelled out a cool $850k in cash for a 5-bedroom cabin-style pad in Ontario, where they live with their dad.

We’re told … this isn’t a case of the family sponging off of Justin — it’s Justin who made the offer to the family.

The house is located way out in the Canadian wilderness in a small town of roughly 8,000 people.

But it’s not like the family is trying to get off the grid — the family name is plastered right on the mailbox.